Piping systems such as those used in steam plants require support which takes into consideration the changes in the position of such piping due to thermal differences. Various forms of spring support devices have been developed for this purpose and include those which are positioned beneath the pipe and those which are suspended from an overhead support, so as to in turn support the piping suspended therefrom. The present invention deals with an improved construction utilizable in both such type supports.
Such devices in either form generally utilize a casing or housing having upper and lower end walls to enclose a spring compressed therein. The spring bears at its lower end against the lower end wall and at its upper end engages a spring backing plate movably mounted within the casing. A load bearing assembly which operatively engages the spring backing plate and which is suspended through an opening in either one of the end walls and to which the load i.e., the piping system can be attached completes the general structure of such spring supports. Supports utilizing casings which are typical of the present state of the art are disclosed in U.S. Pat. Nos. 2,936,142 issued May 10, 1960; 3,148,870 issued Sept. 15, 1964, and 3,615,834 issued May 2, 1972. In such supports, a generally cylindrical casing is provided having a first end wall integrally attached thereto, as by welding; thereafter the spring, its backing plate, and portions of the load bearing assembly, as required, are inserted within the thus partially constructed housing; thereupon the second end plate or wall is welded in position so as to completely and permanently enclose the structure. Accordingly, if it is desirable to re-utilize the device with a spring of a different load capacity or even recycle some of the component parts thereof, such is not readily possible due to the integrally welded closed structure of such known devices. It would accordingly be desirable if spring support devices of this nature could be assembled in such a manner that they could at least be partially disassembled so that the housing portion thereof could be utilized with a different capacity spring or so that the component parts thereof could be re-cycled.
Another serious drawback of the prior art devices of this nature is that they are difficult to protect from rust or other corrosion when utilized in certain commercial environments. Presently such supports are protected by a two-step galvanization procedure wherein the partially enclosed casing is initially galvanized by hot dipping; then, after subsequently welding on the bottom plate, a touchup galvanizing procedure is performed, normally by cold blasting techniques.
Thus, two semicylindrical sides comprising the housing, along with the top cap or end plate thereof, are placed in a welding fixture and welded together to form the partially completed casing assembly which is then provided with an overall protective galvanized coating by standard hot dip techniques. The spring plate and other internal portions such as the load bearing assembly and the other end plate thereof are similarly provided with a hot-dip galvanized coating. The spring, spring plate and portions of the load bearing assembly, as appropriate for the type device, are then assembled within the thus partially completed casing. The spring is then placed under compression by hooks acting thereon through slots provided in the cylindrical wall of the casing so as to draw the spring down away from the open end of the casing. After preparation of the bottom end of the housing, as by removal through blasting techniques of portions of the galvanized coating, the bottom end plate is welded thereto taking care that the heat utilized therein does not destroy any corrosion protective coating on the spring or otherwise change the characteristics thereof. It is thereafter necessary to tough up those welded areas with a protective coating, as by cold galvanizing techniques wherein the metal is projected in a molten condition against the unprotected surfaces, inasmuch as hot-dip techniques cannot be utilized since there will be no practical way to mask the spring.
The above repair process does, however, require masking the spring so that its protective coating, i.e., neoprene, will not be removed in areas coming in contact with the metal flow. This presently used procedure is not only time consuming and expensive but furthermore cannot provide the best possible corrosion protection inasmuch as areas adjacent to the weld area internally disposed within the casing cannot be reached with such repair galvanizing techniques nor is it possible to insure the application of an even protective repair coating to the secondary weld external surfaces. Accordingly it would be particularly desirable to provide a spring support device constructed so that all metal areas thereof may receive an even application of the superior hot-dip galvanized coating without subjecting the spring or its protective coating to the adverse consequences of prior art construction and assembly techniques.